This study assessed the Anti-Stigma Project workshop, a contact/education intervention developed by On Our Own of Maryland, Inc. and the Maryland Mental Hygiene Administration. Two separate randomized controlled trials administered pre- and post-test questionnaire assessments. One included people with mental illness (N = 127) and a second included mental health providers (N = 131). Post-intervention, people with mental illness were more aware of stigma, had lower levels of prejudice, and increased belief in recovery. Providers were more aware of stigma, had lower levels of prejudice, and increased concurrence in self-determination of people with mental illness. Increasing providers' stigma awareness and recognition can promote higher quality service delivery. Increasing stigma awareness and recognition for people with mental illness can foster confidence in overcoming psychiatric disabilities. Using a participatory action research team, our protocol included extant and newly developed stigma change tools. Organizations seeking to conduct effective evaluation studies should consider collaborative processes including the expertise of affected constituents.